Neutrophils have the action of infiltrating inflammatory regions to produce superoxide anions, tumor necrosis factor (TNF)-α which is an inflammatory cytokine, and the like and exacerbate inflammation. It has been suggested that neutrophils are involved in various inflammatory diseases, such as chronic obstructive pulmonary disease (COPD), arthritis, sepsis, ischemic reperfusion injury, and pulmonary fibrosis (Laboratory Investigation, 2000, vol. 80, pp. 617-653). The infiltration of neutrophils is induced by a neutrophil chemotactic factor. In order to treat these diseases, it is thus thought to be important to suppress the production of a neutrophil chemotactic factor and the infiltration of neutrophils.
It has been reported that GPR4 is a G protein-coupled receptor protein (abbreviated to “GPCR” hereinafter) and binds to lipids such as sphingosylphosphorylcholine (SPC) and lysophosphatidylcholine (LPC) to transmit signals and induce the migration of GPR4 expressing cells (Journal of Biological Chemistry (J. Biol. Chem.), 2001, vol. 276, pp. 41325-41335).
On the other hand, known examples of bicyclic heterocyclic compounds include benzazole derivatives which have a hypotensive activity (Japanese Published Unexamined Patent Application No. 73051/1994 and EP520723), benzimidazole derivatives (EP560330 and Japanese Published Unexamined Patent Application No. 360874/1992), indole derivatives (U.S. Pat. No. 5,151,435, EP520724, and EP429257), benzofuran derivatives (EP546449, EP514197, and U.S. Pat. No. 5,789,415), indole or benzofuran derivatives which have an anticephalalgic function (WO93/23396), imidazopyridine derivatives (WO94/12500) and purine derivatives which have a platelet-activating factor inhibitory activity (U.S. Pat. No. 5,861,403), purine derivatives which have a phosphodiesterase IV inhibitory activity (WO99/24432), and benzimidazole derivatives, imidazopyridine derivatives, and imidazopyrimidine derivatives which have an anti-inflammatory activity (Japanese Published Unexamined Patent Application No. 176116/1997).